Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

The design of reliable sensor systems for quick sensing and monitoring the trace concentrations of volatile organic compounds (VOCs) has been a topical area of research in recent years due to their serious menace to living systems and environmental hazardousness. In this article, we report two unique ‘cleft-shaped’ N-aryl-4-amino-1,8-naphthalimide derived Tröger's bases (TBNap-Ph and TBNap-Es) as efficient, fast fluorescence sensors for discriminative sensing of volatile organic amines (VOAs). The fluorescence titration studies using TBNap-Ph and TBNap-Es demonstrated discriminative fluorescence sensing responses for VOAs with high selectivity for benzylamine detection. The initial emission intensity of TBNap-Ph and TBNap-Es was enhanced drastically upon the addition of benzylamine. However, similar titration studies using other VOAs such as n-propylamine, n-butylamine, diethylamine, isopropylamine, 3-dimethylamino-1-propylamine, triethylamine, and ethanolamine elicited poor to negligible changes in the fluorescence emission intensity. The selective ‘turn-on’ fluorescence sensing of benzylamine was also reflected by sharp color changes and these sensors can be used to detect benzylamine at the parts-per-millions (ppm) level of sensitivity. Furthermore, the experimentally observed discriminative fluorescence sensing property of TBNap-Ph and TBNap-Es towards VOAs was supported by computational calculations. © 2023 Elsevier B.V.

World University root node

Department of Chemistry

Journal of Photochemistry and Photobiology A: Chemistry

N-aryl-4-amino-1,8-naphthalimide Tröger's bases-based internal charge transfer (ICT) fluorescence ‘turn-on’ chemosensors for volatile organic amines

A new Tröger's base containing fluorenone organic polymer (TB-FL-COP) was synthesized and used as a fluorescence sensor for discriminative sensing of antibiotics in water. TB-FL-COP showed the highest fluorescence quenching, reversible sensing responses, and excellent sensitivity of 56 ppb level for sulfamethazine antibiotics. The Stern-Volmer quenching constant (KSV) was calculated to be 1.2 × 106 M−1. The fluorescence sensing ability was also reflected by sharp visual color changes and further demonstrated in real water samples. © 2023 The Royal Society of Chemistry

Polymer Chemistry

Tröger's base-containing fluorenone organic polymer for discriminative fluorescence sensing of sulfamethazine antibiotic at ppb level in the water medium

Carbon Nanodots (CNDs) generated from biomass wastes have a wide range of biological functionalities and are used in a variety of applications. Especially, the biomedical applications shown by the CNDs derived from biomass waste materials received great attention from researchers around the globe. Herein we report the synthesis of CNDs from rice husk biomass waste using a hydrothermal method. XRD pattern demonstrates the amorphous nature of CNDs with hexagonal graphite structure. Microscopic images confirmed that as-synthesized CNDs are in spherical morphology with an average size of 25–30 nm and average interplanar spacing of 0.265 nm. XPS, Raman, and FTIR spectral analyses were performed to examine the presence of functional groups and defects in CNDs. Excitation-dependent emission properties of CNDs (ФF 9.6%) were studied by UV–Vis., Contour, and fluorescence techniques. In response to the findings of the cytotoxicity experiment and the CNDs' strong emission, we carried out several biostudies to prove its importance. The CNDs possess outstanding cell viability (98%), excellent anti-inflammatory activity of 33% of LOX, 34% of COX, 45% of NO inhibition at 100 μL, significant protein denaturation (62%; IC50 20.04 μL/mL), and bright bioimaging on Zebrafish characteristics, which accentuate the perception of waste to wealth. © 2023 Elsevier B.V.

Materials Chemistry and Physics

Multipurpose biological applications of excitation-dependent fluorescent carbon nano dots emanated from biomass waste

A cleft-shaped 2-picolyl-4-amino-1, 8-naphthalimide Tröger’s base (TBNap) was synthesized and employed as a fluorescent ‘turn-on’ chemosensor for the discriminative sensing of volatile halogenated solvents based on an ICT sensing mechanism. TBNap displayed comparatively high fluorescence emission enhancement for chloroform - a potent anesthetic agent and a major constituent of tobacco smoke. The discriminative fluorescence sensing was also seen through visual color changes and was further validated using computational calculations. © 2023 The Author(s). Published by the Royal Society of Chemistry.

Sensors and Diagnostics

Discriminative ‘turn-on’ fluorescence sensing of volatile halogenated solvents using a cleft-shaped 4-amino-1, 8-naphthalimide Tröger’s base fluorophore

This article uses a mesoporous organic polymer monolithic template embedded with nanosheets of aurivillius oxide, i.e., Bi2MoO6 (BMO), as a visible light harvesting photocatalyst, for the photocatalytic dissipating for persistent organic pollutants. FE-SEM, EDAX, HR-TEM, SAED, p-XRD, UV-Vis-DRS, FT-IR, PLS, BET/BJH, and XPS analysis were performed to characterize the structural and surface morphological features of the new-age photocatalyst. The unique properties of BMO nanocomposite and a specific quantity (0.75 g) of its integration onto a translucent polymer monolith bring an innovative approach to heterogeneous photocatalysis, with photocatalytic properties far superior and more efficient than non-benign conventional methodologies. The impact of physicochemical parameters such as solution pH, photocatalyst amount, light intensity, pollutant concentration, and oxidizer dosage was evaluated to optimize the process efficacy. The BMO-0.75 dispersed polymer monolith offers superior visible light absorption and voluminous photoactive sites for the dissipation of Reactive Brown-10 (RB-10; = 99.4\%) and ciprofloxacin (CIP; = 98.7\%) at an optimized solution pH (1.0 and 6.0), photocatalyst dosage (50 and 40 mg), and photoadditives (1.0 mM KBrO3 and 1.0 mM H2O2), for RB-10 (15 ppm) and CIP (20 ppm), respectively, in = 0.3 h of irradiation, using 300 W/cm(2) tungsten lamp. The photocatalyst is reusable for several cycles without loss in efficiency and is efficient in decontaminating persistent organic pollutants at an affordable cost and time.

INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY

Photoactive aurivillius oxide integrated porous polymer monoliths as renewable visible light catalyst for decontaminating persistent organic pollutants

In this work, three Co3O4 nanostructures with different morphologies (cubes, rods, and sheets) were synthesized using a hydrothermal method and tested for the CO2 hydrogenation reaction. The physicochemical properties of the structured Co3O4 were well characterized by X-ray diffraction (XRD), Raman spectroscopy, field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), hydrogen temperature-programmed reduction (H2-TPR), and X-ray photoelectron spectroscopy (XPS) techniques. Based on the characterization, cube, rod, and sheet Co3O4 nanostructures were found to expose the (100), (110), and (112) planes, respectively. The effect of cobalt oxide morphologies with different exposed surfaces on the activity and selectivity toward CO2 hydrogenation reaction in a plug-flow reactor operated between 200 and 400 °C under atmospheric pressure conditions was explored. The results establish a correlation of the catalytic activity with morphological structures in the order rods &gt; sheets &gt; cubes. H2-TPR and XPS studies demonstrated that the high reducibility of Co3O4 rod makes it an excellent catalyst for CO2 hydrogenation. © 2023 American Chemical Society.

Journal of Physical Chemistry C

Morphology-Dependent Catalysis by Co3O4 Nanostructures in Atmospheric Pressure Carbon Dioxide Hydrogenation

Reduction of nitroarenes is a useful strategy for the preparation of aromatic amines. In this work, CuO was used as a reusable solid reagent for the reduction of nitroquinolines to aminoquinolines using hydrazine monohydrate as the hydrogen donor under mild reaction conditions. The reaction of 0.5 mmol of 5-nitroquinoline to 5-aminoquinoline was completed in 10 min with 100% conversion and selectivity. The reagent CuO could be easily collected and reused for up to four cycles, after which it is completely transformed into Cu2O and Cu. The high activity and selectivity of CuO were attributed to the facile formation of oxygen vacancies on the CuO surface under the reducing environment, as confirmed by X-ray photoelectron spectroscopy. Further, density functional theory simulations showed that oxygen vacancies led to higher adsorption (Eads = −174.4 kJ/mol) and selective activation of the nitro group (Ea = 43 kJ/mol) coupled with a reaction involving hydrogen atoms activated on the CuO surface. However, the presence of an additional pyridine ring in 5-nitroquinolines slightly impeded the rate of complete reduction (t = 10 min). © 2023 American Chemical Society.

Oxygen Vacancy-Mediated Reactivity: The Curious Case of Reduction of Nitroquinoline to Aminoquinoline by CuO

For a collection F of graphs, the F-CONTRACTION problem takes a graph G and an integer k as input and decides if G can be modified to some graph in F using at most k edge contractions. The F-CONTRACTION problem is NP-Complete for several graph classes F. Heggernes et al. (2014) [4] initiated the study of F-CONTRACTION in the realm of parameterized complexity. They showed that it is FPT if F is the set of all trees or the set of all paths. In this paper, we study F-CONTRACTION where F is the set of all cactus graphs and show that we can solve it in 2O(k)⋅|V(G)|O(1) time. © 2023 Elsevier B.V.

Department of Computer Science and Engineering

Theoretical Computer Science

A single exponential-time FPT algorithm for cactus contraction

Reactions of a dimagnesium(i) compound, [{(DipNacnac)Mg}2] (DipNacnac = [HC(MeCNDip)2]−, Dip = 2,6-diisopropylphenyl), pre-activated by coordination with simple Lewis bases (4-dimethylaminopyridine, DMAP; or TMC, :C(MeNCMe)2), with 1 atmosphere of CO in the presence of one equivalent of Mo(CO)6 at room temperature, led to the reductive tetramerisation of the diatomic molecule. When the reactions were carried out at room temperature, there is an apparent competition between the formation of magnesium squarate, [{(DipNacnac)Mg}{cyclo-(κ4-C4O4)}{μ-Mg(DipNacnac)}]2 and magnesium metallo-ketene products, [{(DipNacnac)Mg}[μ-O = CC{Mo(CO)5}C(O)CO2]{Mg(D)(DipNacnac)}], which are not inter-convertible. Repeating the reactions at 80 °C led to the selective formation of the magnesium squarate, implying that this is the thermodynamic product. In an analogous reaction, in which THF is the Lewis base, only the metallo-ketene complex, [{(DipNacnac)Mg}[μ-O = CC{Mo(CO)5}C(O)CO2]{Mg(THF)(DipNacnac)}] is formed at room temperature, while a complex product mixture is obtained at elevated temperature. In contrast, treatment of a 1 : 1 mixture of the guanidinato magnesium(i) complex, [(Priso)Mg-Mg(Priso)] (Priso = [Pri2NC(NDip)2]−) and Mo(CO)6, with CO gas in a benzene/THF solution, gave a low yield of the squarate complex, [{(Priso)(THF)Mg}{cyclo-(κ4-C4O4)}{μ-Mg(THF)(Priso)}]2, at 80 °C. Computational analyses of the electronic structure of squarate and metallo-ketene product types corroborate the bonding proposed from experimental data, for the C4O4 fragments of these systems. © 2023 The Royal Society of Chemistry.

Chemical Science

Molybdenum carbonyl assisted reductive tetramerization of CO by activated magnesium(i) compounds: squarate dianion vs. metallo-ketene formation

We investigate the indentation of thin adhesive beams by a rigid frictionless circular punch in two-dimensions through computations and experiments. A non-linear geometrically exact (GE) beam formulation that allows for arbitrarily large displacements and rotations is employed for the thin beam. The Karush–Kuhn–Tucker condition for unilateral contact is adapted to model adhesive interaction in a nonlinear finite element (FE) framework. In this, contact is enforced through a penalty method and adhesion is incorporated through two different cohesive zone models (CZMs), viz. exponential and bilinear. The indentation of the adhesive GE beam is then studied in terms of the variations of the applied force, the pressure distribution, the cross-sectional rotation and the sizes of the contact area and the adhesive zone for different indentation extents, adhesive strengths, punch radii, beam thicknesses and end supports. We find that the system is largely agnostic to the CZM utilized, as well as the type of end supports unless the contact area spans the beam. At the same time, thinner beams tend to initiate contact with a punch more easily and are harder to detach. We then demonstrate that thin beams may undergo large rotations even if the indentation is small, which necessitates a nonlinear beam theory. Under such conditions approximating a circular punch by a parabolic one used typically when indentations are small introduces errors. Finally, we conduct experiments on clamped adhesive beams made of two different types of PDMS (polydimethylsiloxane) and various thicknesses and find a good match with our computations. © 2023 Elsevier Ltd